Arc quencher



May 23, 1939.

F. B. ADAM ET AL 9, 5

ARC QUENCHER Filed Nov. 14, 1936 INVENTORS FREDERICK B. flD/IM F20 rp S. GREEN BY 525M.

'ATTORNEY.

Patented May 23, 1939 UNITED STATES PATENT OFFICE S. Green,

poration of Missouri 2 Claims.

This invention relates to arc quenchers which materially reduce the are at circuit rupturing points of switches and circuit breakers. It is an object of this invention to provide arc 5 quenchers which may be applied to knife switches, butt contact type of switches or circuit breakers and other forms of switches and circuit breakers either manually or electrically operated.

Further objects and advantages will appear from the following detailed description. and the accompanying drawing.

Two types of the arc quencher are show the drawing, the one is pa ticularly to the knife blade type of switch'while otl is more particularly applicable to switches or cir cuit breakers employing butt type contacts.

While only two types of the arc quenche s illustrated, it is obvious that the arc quencher is of such a design as to be easily applied to an type of circuit making or breaking device. shape of the arc quencher may be varied to accommodate it to any particular type cuit rupturing device.

In the drawing:

Fig. 1 is a side view of a kniie equipped with an arc quencher.

Fig. 2 is a cross-sectional view on line 2-4 of Fig. 1.

Fig. 3 is a cross-sectional view of a blade switch similar to that shown in Fig. l but pro" vided with a different type of clip assembly.

Fig. 4 is a side view of a switch with enclosed clips and equipped with a suitable arc quencher;

Fig. 5 is a cross-sectional view along line 5--. of Fig. 4.

Fig. 6 is a side view of a portion of a switch w butt contacts and an arc quencher for that particular type of switch.

Fig. '7 is a cross-sectional view along line '-l of Fig. 6.

In the drawing the same reference numerals are used to designate the same parts thrucut all of the figures. The numeral l denotes a switch base of some insulating material with a switch blade switch.

knife blade may be provided with a handle I. switch clip 9 is secured to the base by a machine screw H which screws into a conductor bar it. A piece of insulating paper may be provided 0 insulate the switch clip from the arc quencher l1. Ifhe arc quencher may be formed substanially as shown and of some material of low magetic reluctance such as soft iron or other suitable etals. The ends IQ of the arc quencher extend ver the top of the clip and are so placed as to Adam Electric Company,

blade 3 supported thereon by a support 5. The

ARC QUENCHER Frederick B. Adam, St. Louis St. Louis, Mo..

County, and Floyd assignors to Frank St. Louis, Mo., a cor- Application November 14, 1936, Serial No. 10,824

cause the arc to be quenched when the knife switch is opened.

In many switches the clips are covered by an insulating front often called a dead front and may be or" a type shown in Figs. a l and 5 where the cover or insulating top may be secured to the arc quencher by screws 12 the switch is provided with two clips as shown in Fig. a small piece of metal T23 of the same material as the quencher may be secured to the insulating top so as to extend over the switch clips. An arc quencher suitable for switches of the butt contact type is shown in Figs. 6 and 7 w'. the numeral 25 indicates butt contact, circui ring or breaking contact member rmsitione on the co ducting bar The co-operating butt contact is shown open position at A and in closed position at The are quencher 3193 may be formed substantially as shown of a material of low magnetic reluctance and is provided aclosed end which may be provided with some cooling 11 cans such as holes 33 therein. Fins stances as a cooling means. The open ends is of the arc quencher are held under the conductoi bar l3 by the screw 3 l which screws into the conductor The insulating paper it) maybe provided to insulate the arc quencher from conducting portions or the switch.

Eb has been found in actual operation that quenchersof this design and construction w l materially reduce arcing at switch rupturing points. These are quenchers do not require some rate exciting coils or coiling of the conduc bars of the switching device and hence do not quire the additional space which many other signs of arc quenchers do. Likewise the small and compact design enables them to be used in many more circuit rupturing devices than the conventional types of arc quenchers.

From the above description it can be seen that cover porting base, a stationary contact, a movable contact, and an arc quencher comprising a thin plate of magnetic sheet metal having a central portion positioned under and insulated from the stationary contact and having upwardly extending parallel -side portions on opposite sides of the stationary contact, the side portions of the plate having their upper ends extending inwardly at right angles to the side portions, said end portions spaced apart above the stationary contact to provide a narrow gap for passage of the movable contact, the current through the contacts serving to produce a magnetic field between the opposed end portions of the plate.

2. In an electric switch in combination, a stationary switch clip contact, a movable blade contact and an arc quencher comprising a generally U-shaped plate of thin sheet magnetic metal, said plate having its central portion positioned under and insulated from the clip contact, and its parallel side portions extending upwardly and terminating in opposed end portions spaced apart and above the clip contact providing a narrow gap for passage of the blade and substantially surrounding the clip contact, the current through 10 the contacts serving to produce a magnetic field between the spaced apart ends of the plate.

FREDERICK B. ADAM. FLOYD S. GREEN. 

